1. Field of the Invention
This invention relates to bed sheets that are adapted to facilitate ease of changing and replacing the sheets on a mattress and, more particularly, to a bed sheet set having an upper sheet portion and a lower sheet portion which, in conjunction, enclose the mattress and, further, wherein a waterproof panel is positionable between the upper sheet and the top of the mattress.
2. Discussion of the Related Art
There are numerous combinations of bed sheets which are designed to provide a quick and easy way to change bed linen. Most notably, it is known to provide a fitted sheet which is tailored to provide a tight, neat and wrinkle-free fit when secured to the mattress. The well known fitted sheet design provides elastic material around the corner edges to allow the corner edges to contract on the underside of the mattress in a manner which secures the fitted sheet in place so that the top surface of the sheet is pulled tight and flat on the top sleeping side of the mattress. When it is necessary to wash and change the sheets, the fitted sheet is fairly easy to remove from the mattress by pulling up on the corners. Replacing the fitted sheet on the mattress, however, is known to be problematic, especially if the sheet shrinks after washing and drying. It is often difficult to stretch the fitted sheet over the corners of the mattress in a manner which properly secures the elastic corner edges of the fitted sheet under the mattress. And, even if the fitted sheet is properly secured to the mattress, the corners are sometimes dislodged by the forces of body movement when sleeping.
The problems associated with fitted mattress sheets, having elastic corners, as described above, are of particular concern in the field of baby linen for crib mattresses. Specifically, the need to tuck the elastic edge corners of the fitted sheet around the underside of the mattress requires lifting of a crib mattress out from the crib each time the linens are changed. More importantly, fitted sheets can be easily dislodged from the mattress while an infant is in a crib. Oftentimes the person changing the crib sheets fails to properly secure the elastic corners of the sheet under the mattress, particularly if the fitted sheet shrinks from washing and does not fit easily over the mattress corners. And, even when properly secured to the mattress, fitted crib sheets can be pulled loose by an infant. This is particularly worrisome due to studies which have shown that many cases of Sudden Infant Death Syndrome (SIDS) are a result of smothering due to loose linen, blankets and/or pillows in a crib. For example, if the mattress sheet comes loose, there is danger of an infant becoming entangled or wrapped in the sheet when tossing and turning in the crib, which could possibly lead to suffocation.
The need to frequently change and wash bed linens is especially a concern with infants, small children and elderly bedridden individuals. Accordingly, in addition to the need for a quick and easy way to change bed linen, there is also a need, in many instances, for a linen accessory which provides waterproof properties in order to protect the mattress. With the aging of the population, there is an increasing number of people, both in institutions and at home, who spend much of their time bedridden. For many of these individuals, the bed is used for sleeping at night time and is also used for daily activities (e.g. phone calls, reading, watching television, etc.) while the person is awake. When sleeping, it may be desirable to use a protective sheet having waterproof properties to guard against damaging the mattress at night. However, most waterproof sheets do not provide good airflow through the fabric and become hot and uncomfortable over a period of time. In the instance an individual is confined to the bed during the day, it may be desirable to remove the waterproof sheet in order to provide better ventilation and increased comfort.
In the past, others have proposed various bed linen arrangements for application to a mattress. For instance, Blake U.S. Pat. Nos. 5,086,530 and 4,922,565 disclose a set of bed linen having a top panel that is moisture proof and a bottom fitted sheet that extends partially under a mattress to secure the bottom fitted sheet in the same manner as a conventional fitted sheet. The top panel and bottom sheet have cooperating fasteners that allow the top panel to be removed and replaced from the mattress without disturbing the fitted sheet. The top panel and bottom sheet do not enclose the mattress.
U.S. Pat. No. 6,067,677 to Reen et al. teaches a bed sheet in the form of a pouch with an open mouth. The pouch encloses a mattress. The sheet has a flap which is folded to close the open mouth. The sheet and the flap have cooperating fasteners to hold the flap in place.
U.S. Pat. No. 5,701,617 to Colby teaches a bottom bed sheet folded about a mattress. The bed sheet has two end portions of water permeable textile attached on opposite sides of a moisture resistant center portion. The moisture resistant portion has a textile portion superimposed and fastened to the water resistant portion. The fasteners are releasable.
Accordingly, there remains an urgent need in the art of bed linen for an improved bed sheet arrangement which provides for quick and easy changing of bed linen, while also providing a tight, neat, wrinkle-free and secure fit of the sheets to the mattress. There is a further need in the art for a bed sheet set which remains fitted and secured to the mattress during use and which provides for selective use of a waterproof panel to protect the underlying mattress from contact with moisture and liquids, including bodily fluids.